The International Maritime
Organization (IMO) number is a unique identifier for ships and for
registered ship management companies. For ships, it consists of the three
letters "IMO" followed by the seven-digit number assigned to
all ships by IHS Fairplay constructed. This is a unique seven digit
number that is assigned to propelled, sea-going merchant ships of 100
gross tons and above. It serves to identify ships and is not changed when
the ship's owner, country of registry or name changes. For ship management
companies, the IMO number consists of the three letters "IMO",
followed by a seven-digit number. For example, IMO 8814275 refers
to the ship Eendracht (See insert picture).

Definition

The
IMO ship identification number is made of the three letters "IMO"
followed by the seven-digit number assigned to all ships by IHS Fairplay
(formerly known as Lloyd's Register-Fairplay) when constructed. This is
a unique seven digit number that is assigned to propelled, all passenger
ships of 100 GT and above and cargo ships of 300 gross tonnage and above,
upon keel laying with the exception of the following:

The
integrity of an IMO number can be verified by its check digit,
which is the rightmost digit. This is done by multiplying each of the
leftmost six digits by a factor corresponding to their position from right
to left, and adding those products together. The rightmost digit of this
sum is the check digit.

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IMO
SHIP IDENTIFICATION NUMBER SCHEME

(Circular
letter No.1886/Rev.3)

The
IMO ship identification number scheme was introduced in 1987 through adoption
of resolution A600(15), as a measure aimed at enhancing "maritime
safety, and pollution prevention and to facilitate the prevention of maritime
fraud". It aimed at assigning a permanent number to each ship for
identification purposes. That number would remain unchanged upon transfer
of the ship to other flag(s) and would be inserted in the ship's certificates.
When made mandatory, through SOLAS regulation XI/3 (adopted in 1994),
specific criteria of passenger ships of 100 gross tonnage and upwards
and all cargo ships of 300 gross tonnage and upwards were agreed.

The
implementation of the scheme became mandatory for all ships as of 1 January
1996.

IMO
9319466 on the helideck of M/S Finmaid In May 2005,

In December
2002, the Diplomatic Conference on Maritime Security adopted a number
of measures aimed at enhancing security of ships and port facilities.
This included a modification to SOLAS Regulation XI-1/3 to require ships'
identification numbers to be permanently marked in a visible place either
on the ship's hull or superstructure. Passenger ships should carry the
marking on a horizontal surface visible from the air. (See insert picture)
Ships should also be marked with their ID numbers internally.

The IMO ship identification number is
made of the three letters "IMO" followed by the seven-digit
number assigned to all ships by IHS Fairplay (formerly known as Lloyd's
Register-Fairplay) when constructed.

This
is a unique seven digit number that is assigned to propelled, sea-going
merchant ships of 100 GT and above upon keel laying with the exception
of the following: